From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [PATCH 1/3] Only call aio flush handler if set Date: Mon, 22 Sep 2008 21:38:07 -0500 Message-ID: <48D8568F.2060206@us.ibm.com> References: <1222125454-21744-1-git-send-email-ryanh@us.ibm.com> <1222125454-21744-2-git-send-email-ryanh@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org To: Ryan Harper Return-path: Received: from e32.co.us.ibm.com ([32.97.110.150]:55949 "EHLO e32.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754159AbYIWCjI (ORCPT ); Mon, 22 Sep 2008 22:39:08 -0400 Received: from d03relay02.boulder.ibm.com (d03relay02.boulder.ibm.com [9.17.195.227]) by e32.co.us.ibm.com (8.13.8/8.13.8) with ESMTP id m8N2V8BJ014086 for ; Mon, 22 Sep 2008 22:31:08 -0400 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay02.boulder.ibm.com (8.13.8/8.13.8/NCO v9.1) with ESMTP id m8N2d7nU200316 for ; Mon, 22 Sep 2008 20:39:07 -0600 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m8N8d6Xp003275 for ; Tue, 23 Sep 2008 02:39:07 -0600 In-Reply-To: <1222125454-21744-2-git-send-email-ryanh@us.ibm.com> Sender: kvm-owner@vger.kernel.org List-ID: Ryan Harper wrote: > If the aio handler doesn't register an io_flush handler, we'd SEGV; fix that by > only calling the flush handler if set. BTW, aio handlers *should* register an > io_flush routine. > > Signed-off-by: Ryan Harper > > diff --git a/aio.c b/aio.c > index 687e4be..2bb3ed4 100644 > --- a/aio.c > +++ b/aio.c > @@ -105,7 +105,8 @@ void qemu_aio_flush(void) > ret = 0; > > LIST_FOREACH(node, &aio_handlers, node) { > - ret |= node->io_flush(node->opaque); > + if (node->io_flush) > + ret |= node->io_flush(node->opaque); > } > Just not doing an io_flush is just hiding the real bug--that the user didn't register an io_flush handler. If the inevitable SEGV is not your thing, I'd rather see a check added to qemu_aio_set_fd_handler() that threw an error and exited if called without an io_flush handler. Regards, Anthony Liguori > qemu_aio_wait(); >